# Universal relations for gravitational-wave asteroseismology of proto-neutron stars

## TL;DR

This paper derives universal, EoS-independent relations linking proto-neutron star oscillation mode frequencies to fundamental properties, enabling inference of star characteristics from gravitational-wave data.

## Contribution

It introduces universal relations for PNS oscillation modes that are independent of EoS, neutrino treatment, and progenitor mass, facilitating gravitational-wave based property inference.

## Key findings

- Universal relations relate mode frequencies to surface gravity and mean density.
- Relations are independent of equation of state, neutrino physics, and progenitor mass.
- Potential to infer proto-neutron star properties from gravitational-wave observations.

## Abstract

State-of-the-art numerical simulations of core-collapse supernovae reveal that the main source of gravitational waves is the excitation of proto-neutron star modes during post-bounce evolution. In this work we derive universal relations that relate the frequencies of the most common oscillation modes observed, i.e. g-modes, p-modes and the f-mode, with fundamental properties of the system, such as the surface gravity of the proto-neutron star or the mean density in the region enclosed by the shock. These relations are independent of the equation of state, the neutrino treatment, and the progenitor mass and hence can be used to build methods to infer proto-neutron star properties from gravitational-wave observations alone. We outline how these measurements could be done and the constraints that could be placed on the proto-neutron star properties.